Rotary pressure or vacuum pump



(3. L. MCGUEN ROTARY PRESSURE OR VACUUM PUMP Filed Nov. 1, 1919 2 SheetSmSheet 1 G. i... MCCUEM ROTARY PRESSURE OR VACUUM PUMP Ami 29 2 Sheets-Sheet 2 M I W/////// .liiiili H fin 5\ MW m v x Q Q% u QM pump employing an Patented Apr. 29, lfiZd.

hi i T E Q;

CHARLES L. MOCUEN, F EVANSTON,

TODELCO-LIGHT'COMPANY, OF DAYTON, OHIO,

i, an

ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS,

A conrona'rion or DELAWARE.

ROTARY PRESSURE 0R VACUUM PUMP.

Application filed November 1, 1919. Serial no. 335,033.

To all whom it may concern:

Be it known that 1, CHARLES L. MoCUnx, a citizen of the United States, residing at Evanston, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Rotary Pressure or Vacuum Pumps,of which the following is a specification.

The invention-relates to rotary pressure or vacuum pumps, and the object of the invention is to provide a' rotary pressure or 'TilClllllil pump in which the friction will be reduced to the minimum and the maximum efliciency obtaine d from the pump for a given expenditureof power.

It is a further object of the invention to provide in a rotary intermesliin g pair of gears mounted to rotate upon anti-friction bearings an improved construction to prevent internal leakage in the pump.

A further object of the invention'is to improve the generalconstruction of the various component paits of the pump casing containing the inlet and outlet headers for both the fluid refrigerant and the pump sealing and lubricating fluid, thereby securing-certain described advantages and economies in manufacture, installation, opera tion, and in making any necessary repairs to the pump subsequent to installation.

Other objects of the invention will appear from the preferred embodiment of the invention as set forth in the following speci fication, which is also depicted in the ac companying drawings.

In carrying out the invention a pair of gears aresemployed, which mesh with each other and rotateinppposite directions, the gears being housed in a casing with an ad mission port at one side. and an exhaust port at the other. The gear casing is preferably submerged in aliquid having access through restricted passages to the discharge side of the gears, but being excluded from the inlet side; The gears lit with a working'lit within-the casing and the liquid acts as a seal to prevent any leakage past the gears and prevents the passage of any gas from the inlet to the discharge, other than that "which is carried in the space between the teeth of the gears. I

In thesaid drawings, Fig. 1 is a side elevation View of the pump with a portionoi the discharge or exhaust pipe broken away pressure or vacuum and with the admission duct and valve mechanism controlling same in section.

Fig. 2 is a sectional view on line 2-2 of Fig. 1 looking in the direction indicated by the arrows.

Fig. 3 is a longitudinal sectional view on broken line 3-3, taken in the direction indicated by the arrows.

Figs. i to 8 inclusive are perspective views showing details of some of the component parts serving as end closures, bearing supports and portions of the inlet and outlet headers of the casing.

In the preferred form of the invention embodied in the pump herein shown and described, the pump mechanism is contained in a casing of special design adapted to be attached to the wall of aclosed chamber, the body or barrel o'f the pump enclosing the operating gears being adapted to be located within the chamber, there being ahead casting a provided with'a peripheral flanged portion 10 adapted to be secured on the exterior of the chamber wallsurrounding an opening therein that will be formed to permit the passage of the body portion of the pump therethrough, the pump barrel or casing proper protruding on the interior of the chamber, notherein shown, as the same forms no part of the invention, for the pump may obviously be attached to its support in any other desired manner. The flanged portion 10 of the head casting ais provided with a plurality of spaced openings 11 through which its securing bolts are passed, and the body portion of the head casting a will be preferably formed as illus trated as a substantial continuation of the design in cross section of the parts making up the pump barrel or casing proper enclosing the pump gears, so that when the pump is installed. by being bolted to its enclosing chamber wall, the opening ,in. the chamber wall will be closed by the body of head casting a, and the opening sealed by reason of the peripheral flanged portion 10 and suitable packing as desired, as well understood in the art, and not herein shown. The head casting a is provided with a boss 12 (Figs. 1 and 3) adapted to protrude on the exterior of the pump when installed,

' there being an opening through the entire longitudinally, and in which a suitable been 'ing therefor is provided by contracting the opening on the side of the casting adjacent the interior of the pump barrel as indicated at 13 'the said opening being enlarged outwardly to the extreme outer end of the boss 12, where it is screw threaded, as indicated at 14, for the reception of a combined hearing member and packin gland closure plug screw threaded, and a apted to co-operate therewith, the same being indicated by reference character 15, and having preferably :2 its outer extremity a portion angular cross section as indicated at 16 for the reception of a tool to be used in adjusting the same in relation to the head casting, it

' being adapted to be secured in its adjusted pum , ing h provide erant which the "pump is particularl c0 1 1 as indicated byreferencecharacter 22 shown v particularly in vertical section in Fig. 1, the inlet passage 23,,thereof being provided chines, mm

position'by lock nut 17.

In -a pump ofthe described character, it is very desirable that this bearing for the operating shaft be constructed to prevent leakage of fluids from the interibr of the and hence the desirability of elongate acking gland and bearing as herein d the s ace between the contracted and gland closureplug 15 surrounding the shaft being preferably filled with a suitable packing material asa coil oflibrous cord or rope indicatgd by reference character; 18, wound circumferentially of theshaftso that whatever pressure thereon desired may be secured by the adjustment of the closure plug bearing,16. As a further means of securing a fluid tight joint around the drive shaft 1; within the gland, I find it advantageoustto insert with the packing one or more rings of some soft ductile material,

A lead being preferred, as indicated by reference character 19, the same being adapted to closely surround the drive shaft 6 and also to contact with the wall of. the gland housing. At right angles to the axis of the bearing for the .shaft b in the head casting a and in the boss 12 thereon there is aduct or passage 20, the same extending through the body of the boss 12 adapted to serve as an inlet passageway for the fluid refri adapted to, circulate, as sulphur ioxide (S0,), and extending at right an les to the passage" 20 v and parallel with the drive 'shaft through-the body of the head casting a; and boss 12 thereon is the communicating passageway 21 through which fluid refrigerant will be passed to the interior of the pump or casin' kbeing introduced into the passage 20 mmon in refrigerating ma ipe forming a part of the circulatory'ieystempf the machine'and communicatingzwitli" ,the valved fitting therein with the contracted portion or seat 24 adapted to be closed by suitable means, as

the ball valve 25 normally held againsts'aid of the pump, thus preventing any return flo'w from the pump through the circulatory system supplying same, but opening to supply fluid to the pump. The valve. fitting 22 is screw threaded-into the boss 12 closing one end of the passageway 20 on the exterior ofthe boss'while the other extremity of the passage 20-is closed by a suitable plug or stop cock as indicated at 27 be formed as a pipe fitting. and serve as a connection for t e attachment of 'means for charging the s 'pump will be connec in series as described, with an initial supply or renewal supply of fluid refrigerant.

which may' adaptedto 3 m, in which my venience in manufacture, of a composite character, one of the gears being secured to rotate with drive shaft 6 and consisting of composite parts 28 and 29, while a second composite gear shown as, made'up Of'thfl parts 30, 31 rigidly secured to a shaft e ex tending beyondthe extremity of the gear a portion to form journahor trunnion portionsifor engagement with its bearing suppreferablwhavetheir teeth arranged in what ma double spiral fermati \il l%sg;rated for example in U. S. Pat ent 1,2 3, tLgjranted July 10, 1917 to G. I. Leonard, an *being adapted to rotate when normally operating a in the directions indicated by the arrows in Fig. 2, so that as the pockets formed in the gears between their teeth move out of interontgs. "fhe intermeshing gears 28, 29 'ande er e herring-bone orv lin -as meshing relation with the opposing gear teeth the fluid in the inlet 32 communicating with intake passage 21 for the refrigerant is sucked into the gas pockets between the teeth and thence carried therein up and around the gears as the latter revolve to be later acted upon bythe' gear teeth which intermesh with these pockets or spaces the-1'15 tween the teeth on the reverse side of the gears, this intermeshin'g action being a progressive one, so that alsAthe gears'continue to rotate, the' fluid, co ing through intake passage 21' and inlet 32formed. as a roove on the inner surface of main gear enc osing casing f and extending longitudinally of y the casing and communicating throughout.

the length of the gears, is forced fromthe inner ends of the pockets or spaces between the teeth of the gears toward the ends there-f of at the ends or outer extremities of .the

gears adjacent the end walls of the gear cas a ing, the fluid in this'operation passing first' downwardly through passageways 33 and 34 to the common duct or discharge passage emes an in casing f, which communicates with the pump discharge p1pe'36, which may be exi tended to any convenient point'oi discharge for the fluid being compressed or pumped. 'Passageway 33 18 formed merely as a recess on the inner pump chamber side of an end plate 0 while the passageway 84 is a similar gear shafts, b and e designated by the refer encecharacters 4:1 and 4:2 in the former and by' reference characters 43 and 1-1- in the lat ter. designed to receive and retain in posi-- tion suitable anti-friction bearing devices as indicated generally by reference characters 45 to 4-8 inclusive, as shown in section in Fig. 3.

The construction described affords an admirable means for supporting and retaining'the ball bearings in correct position and the fact that the composite pump casing is madeup of the various integral parts, described, makes these hearings easily accessible when the pump is disconnected. Each of the component parts of the pump casing comprisingplates 7,0, main gear casing 7, plates cl,g,and ii) are provided with registering openings, four in number, designated as follows: 1

reference characters 61 to 64- inclusive and in end plate It by reference characters 65 to '68 inclusive, these plates being assem bled'in the order named and as indicated in Figs. 1 and 3 in a unitary assembly. which may be independent of the head casting a,

by the four elongated securing bolts 69 to- 72 inclusive, each of which'is provided with suitable securing nuts, and locking devices, if desired, as illustrated.- The elongated bolts 69 to 72 inclusive may be provided with heads protruding on the outside surface of bearing plate j, which heads are adapted to be accommodated in the assembly by counter sunk portions or recesses as indicated at'73, Fig. 1, so that the assembled pump casing may then be attached to the headca'sting a by suitable retaining bolts, the heads or nuts of which are shown only in Fig. 1, and indicated by reference characters 74, 75, there being preferably four or more of such securing bolts used. the same being passed through the openings to to 7'9 inclusive, and registering with similar openings in head casting a. I

is abattle plate which may be secured around the discharge pipe 36 near its union with the pump casing the union being prcfcrably secured by means of a suitable cou necting casting as indicated. at 7., which may be secured in position with the orifice 81 therein, registering with the discharge pas sage from the pump casing of which the opening 30 in the outer end plate hforms a part, as described.

The gnu-pose of the baffle plate 80 is to prevent an upward current or circulation of any fluid or gaseous refrigerant that might become mixed with the liquid in which the pump is normally imu'iersed when in operation.

The operation of the device has been alluded to iu'the description of the details of construction. and it will be understood that the rotation of the gears in the direction in dicated by the arrows in Fig. 2 and by rcason of the fact that these gears are designed to be sealed by means of some suitableliquid, as lubricating oil, to be admitted through the vertical ducts or pipes 82 to 86 inclusive, lherobeing eight of such liquid pipes on the type of pump herein illustraled, live of which are shown by reason of the character of drawings in side elevation and section, Figs. 1 and 2, will cause these gear teeth to separate or Withdraw on the upper side thereof as illustrated in the drawings, causing a vacuum and exerting a pull upon fluid re 'g'erant past the ball Valve 25 into the duct 32. which will be carried around the periphery of the gears to the lower sides thereof to be discharged, by reason of the herringbone construction of the neura pmgressivcly in an outward direction and 'ito the passageways 33 and and through the outlet duct ll) from the pump. 'lhe liquid intake tubes 86 protrude downv/ardl from the. using and there are detachablev nbes provided with specially constructed contracted discharge orifices as indicated by reference character 87. F 2, the tubes detachable by threading the ends of. same adjacent the said orifices and inserting same in correspondingly threaded openings in main gear casing f having the fluid except as supplied through the gradu-.

ated and readily selected ducts 87 in the feed tubes, no more of the sealing fluid may be admitted than will properly function.

It is found in practice that the amount of sealing liquid to properly supply the pump can be determined by graduating the openings 87 in the oil feed tubes for a given condition of oil or other liquid and for given temperature. conditions, hence the reason for making these tubes detachable and permitting the interchange of tubes. with the {lesired feed orifices therein as may be reguired to accommodate any particular conition.

Obviously, the discharge of fluid entering through intake passage 32 will have co mingled therewith in the discharge passage 35 and the passage 40 leading from the pump. a quantity of sealing fluid as the oil, together with the refrigerant or other fluid being pumped, the refrigerant being usually a fluid in the form of a gas and will pass after discharge into the space above the oil .orother liquid refrigerant in which the pump is immersed. 4o.

ed gear shafts b and e. 94 indicates a series 91 indicates threaded lock rings on threadof' re istering aligning holes adapted to take owel pins in connecting the various parts of the pump casing together.

The outer end of'drive shaft 6 is shown provided with one part of a. partially fiexible cou lingincluding plate 92 secured to power supplying shaft not shown.

While I have shown and described the preferred embodiment of my invention, it

will be apparent that persons skilled in the art may vary the details without departing from the purpose and spirit of the invention, and what Icla-im as new and desire to secure by Letters Patent is:

1. A. fluid pump comprising. in combination, a gear casing and closely fittin'g intermeshi'ng gears rotatably mounted therein,

' there being an inlet passageway on one side of the intermeshing portions of said gears, and a discharge passage leading from adjacent the said inter-meshing portions of the gears and from the casing, and means aetuated by the pump for feeding by suction action a suitable sealing liquid to the gears comprising a member of tube-like formation detachably secured adjacent an opening passing through the walls of ,said. casing.

2. A fluid pump comprising in;combination a gear casing andclosely fitting intermeshing gears rotatably mounted therein,

there being an inlet passageway on one side of the inter-meshing portions of said gears and a discharge passage leading from adjacent the said inter-meshing portions of the gears and from the casing,.and. means actuated by the pump for-feeding bysuction action a restricted volume of a suitable se'aling liquid to the gears comprising a detacha-..

ble member of tube-like formation having an opening extending longitudinally thereof, there being a restricted passageway forming a continuation of the normalopening in the said tubular member,

3. A fluid pump comprising in combina- A tion a gear casing and closely fitting intermeshing gears rotatably mounted therein for pumping the refrigerant, said gear casing being provided on the interior thereof with two substantially cylindrical, chambers, the

axes of which are arranged in parallelism and the peripheries of the circumferential portions of said chambers intersecting, whereby the said gearsmay intermesh, there being an inletpassageway formed in the inner wall of said gear casing adjacent the intersecting portions of said geanfchamr.

bers, the said passageway extendin approximately parallel with the axes o v sa d gear chambers, closure plates adapted for attachment with the ends of the gearcasing adjacent the said chambers therein, means for detachably securing said end' closure plates to the gear casing, means for feeding fluid to be pumped through the closure at one end to t for conducting fluid from adjacent the gears through the end closure plates and the said casing" to the exterior of said pump, said gear casing being provided with an aperture and means whereby a sealing fluid may be intro:

e said'inlet passageway, means I duced through said aperture into said casing by the suction of said pump only.

A fluidpump comprising in combination, a gear casing and closely fitting intermeshing gears rotatably mpunted therein, sald gear casing being provided on the interior thereof with two substantially cylindrical chambers the a'xes of wh ch are arranged in parallelism and .theperipheries of the circumferential portions. of said chambers intersecting whereby the said gears =may intermesh, there being an inlet passage:

way formed in the inner. wall of the said gear casing adjacent-the'interseeting por-- tions of said gear chambers, the said passage- Way extending approximately aral el with the axes of said gear chem rs, closure menses plates adapted for attachment with the ends of, the gear casing adjacent the said chambers therein, means for detachably securing said end closure'plates to the gear casing, means for feeding fluid to be pumped through the closure at one end to the said inlet passageway, means for conducting fluidfrom adjacent the gears through the end closure plates and the said casing to the exterior of said pump, said gear casing being provided with an aperture, and means whereby a sealing fluid may be introduced through said aperture into said casing by the suction of said pump only and means for rotatably Y supporting said gears.

5/A fluid pump comprising in combination a gear casing and closely fitting intermeshing gears rotatably mounted therein, said gear casing being provided on the interior thereof with two substantially cylindrical chambers, the axes of which are arranged in "parallelism and the peripheries of the circumferential portions of said chambers intersecting whereby the said gears may intermesh, there being an inlet passageway formed in the inner wall and at the top of said gear casing adjacent the intersecting portions of said gear chambers, the said passageway extending approximately parallel with the axes of said gear chambers, closure plates adapted for attachment with the ends of the gear casing adjacent the said chambers therein, means for detachably securing said end closure plates to the gear casing, means for feeding fluid to be pumped through the closure at one end to the said inlet passageway, and means for permitting the passage of a restricted volume of a suitable sealing liquid through the walls of the gear chambers therein at the lower portion thereof.

, 6. A fluid pump comprising in combination a gear casing and closely fitting intermeshing gears rotatably mounted therein, means for rotating said gears comprising in part a drive shaft operatively connected with one of said gears and extending on the exterior of the gear casing, said gears having teeth on the peripheries thereof disposed obliquely or in herring-bone relation with the vertex of their angle at their first point of contact, there being an inlet passageway formed on the interior of the easing on one side of the intermeshing portions of said gears and in communication with said intermeshing portions oi": said gears from end to end of said gears and discharge passages formed in the end walls of the gear casing, there being one of said discharge passages at each end of the gears adjacent their contiguous or intermeshing portions and on the side of their point of engagement 0 posite to that of the inlet passe sway, t ere being a duct connecting and recharge passages, and me tor vent said gear casing, there being an inlet pas sage, formed in certain of said end closure plates and communicating with a groove formed on the interiorwall of the gear casing, there being outlet passages formed also in certain of said end closure plates, said outlet passages opening into a common discharge passage formed in the. casing wall but out of communication except through said passageways with the interior of the pump casing, and means for venting the said common discharge passageway on the exterior of the pump casing.

8. A fluid pump comprising in combination, a gear casing and closely fitting intermeshing gears rotatably mounted therein, there being inlet and outlet passageways in communication with said gears for fluid to be pumped, the inlet passageway being formed as an extension on the inner wall of the casing and communicating with the interior thereof adjacent the point of contact of said intermes'hing gears at one side thereof, detachable plates for closing the ends of said gear casing, there being exhaust ports formed in the walls of certain of said end closure plates and opening at the opposite side of the gears from the said inlet passageway, said exhaust ports opening into a common passageway formed in the casing wall and out of contact except through said exhaust ports with the interiors of the pump casing, and means for permitting the entry of a restricted volume of suitable sealing liquid to the gears on the interior'of the pump casing.

. 9. A flnid'pump comprising in combination, a gear casing and closely fitting intermeshing gears rotatably mounted therein, end closure plates adapted to close the open ends of the gear casing, said plates being provided with openings therein adapted to permit the passage therethrough of suitable shafts for rotatably supporting the said in termeshing gears, bearing plates adapted to be secured to the ends of said casing on the respective exterior surfaces of said end closure plates, there being enlarged openings in said bearing plates around the shafts for supporting said gears, anti-friction hearings in said enlarged openings in the bearing plates, and means for securing said bearing plates, said end closure plates and said gear casing together to form a substantially rigid pump casing.

10. A fluid pump cbmprising a and intermeshinggears retetahly meted casin therein, said casing having an inlet passage above the line of intermesh of the gears, and discharge passages located at the opposite ends of the gears and connected by a passage below' the line of intermesh of the gears.

'- '11. A fluid nun) com r1s1n a casln b and intermes'hing gears rotatably mounted therein, said casing having an inlet passage above the line of intermesh of the gears, and discharge passages located at the opposite ends of the gears and connected by'a passage below the 'line of intermesh of the gears, and means for.v supplying a sealing '15 liquid in restricted volume to the lower plates, platessides of the gears at points prior to the discharge of the refrigerant therefrom.

12. A fluid pump com rising a casing.

v CHARLES-I43; MoCiJEN. 

